Art of making hollow hard-rubber articles.



UNITED STATES WILLIAM W. WEITLING, OF COLLEGE POIN T,

PATENT oFFr-on AMERICAN. HARD RUBBER QOMPANY, A-OORPORATION OF NEW YORK. ART OF MAKING HOLLOW HAR -R BER ARTICLES.

Specification of LettersPatent. Application filed March 19. 19Q6. Serial No. 5061771- I Patented July 31,1906.

I To all whom it may concern:

: trate the invention;

Be it known that 1, WILLIAM W. WEITLING, a citizen of the United States, and a resident of College Point, county of Queens, and State of New York, have invented certain new and useful Improvements in the Art of Making Hollow Hard-Rubber Articles, of which the following is a specification.

My invention relates to the art or method of making hard-rubber articles having inte rior cavities. Its object is to provide a method by which the heating fluid, as steam, used in vulcanizing the articles may be admitted to the interior of the cavity so as to equalize the pressure and prevent collapse of the article before the completion of the process of vulcanization, at the same time-making the aperture so small that it will beinconspicuous in the completed article.

' The invention relates particularly to the method of manufacture of such hollow artiples as are vulcanized between sheets of tin oil.

In the drawings, Figure 1 represents a blank for making onehalf of the completed article during'an early stage of its manufacture. Fig. 2 is a partial' view of a similar blank, showing a modification of the application of my invention. Fig. 3 is a partial view of a comb-blank cut away to more fully illus- Fig. 4 is an end view of thecomb-blank shownin Fig. 3.

Referring to Fig. 1 of the drawings, it may be stated that in making the hollow article chosen as the subject of illustration by this process sheets of soft unvulcanized rubber (designated as 10) are placed between a layer of relatively thick tin foil 11 and a layer of lighter tin-foil 12. he packs so made up are then pressed between dies to form onehalf of the article having the desired cavity therein, as shown in Fig. 1 of the drawings. After the preliminary pressing operation,

. which is performed in a suitable die, the sheet of tin-foil 12, which covers the concave or hollow side of the article, is stripped off and two of the blanks are placed face to face with their concave sides together, the gum por tions' 10 being united and registered by means of the apertures 13, pierced" through the blanks or in any other desired manner. The two halves 10 so placed together and each covered on its outer side by the tin-foil sheet 11 are then again pressed in a die to firmly them into hard unite the sheets of gumlO, except where they NEW YORK, ASSIGNOR To are concaved or hollowed at 14, and. the articles are then placed in a vu1canizing chamber I to which steam is admitted for vulcanizing rubber in the usual wellknown manner. Under the present invention, however, before placing the two halves together the ends of the sheets 11. aregcut off,e. g., as indicated by the linew x and, a pin or wire 17 is placed on one sheet extending from the cavity 14 to the end of the sheet, as shown in the drawings. The two halves are then ressed together,;as above stated, after w "c the pin is withdrawn, thus leavmg a very small aperture 17, connecting-the cavity 14flwith the atmosphere. The united halves,with their foil covering, are then placed or hung in the vulcanizing-chamber; It is obvious that the aperture 17 permits the ingress of steam or heated vulcanizing fluid to the interior of the cavity, so that the pressure is equalized and any danger of collapsing the halves together is prevented. v

Fig. 20f the drawings represents a slight modification of the method offsecuringthe desired aperture betweenthe cavity 14 and the periphery of the articles after they. are pressed together, in which the pin 17; is first incased unvulcanized rubber the ends of the sheets incased pin or wire is the two halves united able die, and the pin being, as above stated, to leave a suitable aperture for the ingress of steam to the cavity 14. This second method is sometimes advantageous in that the casing 18, while of soft unvulcanized rubber, may be somewhat drier than the tacky material of which the sheets 10 are composed, so that the withdrawal of the pin is facilitated and the vent hole or aperture is more certain to remain open during the necessary handling and during the process of vulcanization.

18. After cutting oif along the' line y' the placed in a recess 19, by pressing in a suit Both Figs. 1 and 2 of the drawings show a, I half-blank in which there are two cavities 14. It is obvious that both are provided before vulcanizing with means providing the apertures above described.

Fig. 3 of the drawings represents a vulcanized article 20, which in the present instance is a comb-blank, ready to have the teeth out withdrawn, the object bywrapping around it a thin sheet of therein. It will beseen that from the cavity TOO ' purpose of equalizing the pressure.

so small, as shown in Fig. 4, that 14 to the end of the back of the comb proceeds a small aperture 21, which is, however, when the extends from the cavity of the article to the periphery of the foil covering; withdrawing the pin; and subjecting the article to the accomb is completed it will be inconspicuous tion of a heating fluid for vulcanizing the and will not require filling or lugging by means of cement, rubber, or the ike.

I am aware that it has heretofore been customary to vulcanize hard-rubb er articles consisting of two halves or parts and that an aperture was made in one of these for the admission of steam or a heating fluid for the Such a device is shown in the patent to Smith, No.

. 220,947, dated October 28, 1879. In that patent the aperture is shown as of considerable size, as it was intended to serve both to eq ualize the pressure and to afterward perimit the introduction of a liquid or viscous cement into the interior of the article. Such a relatively large aperture was required to be filled with cement or rubber after the article was completed. The present invention provides for the making of so small an aperture .as to be inconspicuous by the insertion between the halves of the blank before the final j" ressing operation of a pin of small diameter,

small aperture,

which is afterward withdrawn, leaving a very as above described. I

I have spoken of the sheet 10 and casing 18 as being made of rubber, by which it will of course be understood that any well-known rubber compound suitable for vulcanization is intended.

What I claim is- 1. A method of making hollow rubber articles comprising: forming at least two separate concave-faced portions of the article between layers of tin-foil; stripping off the foil from the concave faces of each of the separate portions; placing these portions in having first placed same.

2. A method of making hollow rubber articles comprising: forming at least two separate concave-faced portions of the article between layers of tin-foil; stripping off the foil from the concave faces of each of the separate portions; incasing a pin of small diameter with a layer of unvulcanized rubber; placing the portions of the article in contact and uniting them, having first placed between them such incased pin; withdrawing the pin, leaving its casin extending from the cavity in the article to the periphery of the foil coverin and subjecting the article to the action of a eating fluid for vulcanizing the same.

3. A method of making hollow rubber articles comprising: placing each of two layers of unvulcanized rubber between two sheets.

of tin-foil shaping each of said sheets so covered with foil in a die to form one concavefaced side of the article to be made; stripping off the foil from the concave faces of each of said sides; placing said faces together and uniting them by means of a suitable press, having first placed between them a pin of small diameter which extends from the cavity of the article to the periphery of the foil covering; withdrawing the pin; and subjecting the article to the action of a heating fluid for vulcanizing the same.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

WILLIAM W. WEITLING.

Witnesses:

Ms A. GILEs, JNo. A. DICKSON. i" 

